PA law on involuntary manslaughter, the reckless regard for life resulting in a death. Seems like a guy is lying there helpless, passed out and injured, and you punch him in the gut, and he subsequently dies, you did not try and get him help, might fall under this category.
http://statelaws.findlaw.com/pennsylvania-law/pennsylvania-involuntary-manslaughter-laws.html
http://statelaws.findlaw.com/pennsylvania-law/pennsylvania-involuntary-manslaughter-laws.html